Quantitative and qualitative analysis of compounds and molecules is an important task. One type of analysis is the detection of chemical and biological compounds using, for example, radioactive labeling. Chemical compounds and biological molecules are radioactive labeled to form tracers. The radioactive compounds, molecules, and their metabolites are then followed through the body and observed for emitted radioactivity. This type of detection, however, has limited sensitivity and requires expensive safety and precautionary measures.
Like reference numbers and designations in the various drawings indicate like elements.